Cosmetic skincare is primarily understood as meaning that the natural function of the skin as a barrier against environmental influences (e.g. dirt, chemicals, and microorganisms) and against the loss of substances intrinsic to the body (e.g. water, natural fats, electrolytes) is strengthened or restored.
Impairment of this function may lead to increased absorption of toxic or allergenic substances or to attack by microorganisms, leading to toxic or allergic skin reactions.
Another aim of skincare is to compensate for the loss by the skin of lipids and water caused by daily washing. This is particularly important when the natural regeneration ability is inadequate. Furthermore, skincare products should protect against environmental influences, in particular against sun and wind, and delay skin aging.
Medicinal topical compositions generally comprise one or more medicaments in an effective concentration. For the sake of simplicity, for a clear distinction between cosmetic and medicinal use and corresponding products, reference is made to the legal provisions of the Federal Republic of Germany (e.g. Cosmetics Directive, Foods and Drugs Act).
Customary cosmetic and dermatological preparation forms which have become ever more widespread in recent times are gels.
In simple emulsions, finely disperse droplets of one phase (water droplets in water-in-oil (W/O) emulsions or lipid vesicles in oil-in-water (O/W) emulsions), surrounded by an emulsifier shell, are present in a second phase. The droplet diameters of customary emulsions are in the range from about 200 μm to about 50 μm. Such “macroemulsions” are, without further coloring additives, milky white in color and opaque.
The use of customary cosmetic emulsifiers is in itself safe. Nevertheless, emulsifiers, like ultimately any chemical substance, may in individual cases cause allergic reactions or reactions based on user hypersensitivity.
For example, it is known that certain photodermatoses are triggered by certain emulsifiers, but also by various fats, and simultaneous exposure to sunlight. Such photodermatoses are also called “Mallorca acne”. One object of the present invention was therefore to develop sunscreen products.